1. Field of the Invention
The present invention relates to fluid flow systems and more particularly to lawn type sprinkler systems having an automatic control device to shut-off a sprinkler head in the event of a malfunction.
2. Description of the Prior Art
Lawn and grass areas are typically irrigated by in-ground sprinklers, which mayor may not pop-up when water flows from a supply source. Most systems are automatically operated either by a timer or by some type of ground moisture sensing arrangement.
Conventional sprinkler heads are prone to breakage for a variety of reasons. For example, sprinkler heads may be run over by lawn mowers or be stepped on by a person walking across the lawn.
Breaking one or more of the sprinkler heads results in the majority of the water in the system being disbursed through the broken heads, instead of all of the heads as programed. This is not only a waste of water, but can be quite expensive in areas where water shortages are common. Water is a precious commodity in many areas, such as desert developments and the like. In addition, the area around the broken sprinkler head can be damaged by the excessive water flow to this area. With automated systems, breakage of a sprinkler head is often not detected until extensive damage occurs. Moreover, the entire system may be shut down until appropriate repair can be made, thus causing other areas which need the water to be damaged.
The prior art has attempted to address these problems. Various examples of prior attempts are listed below.
U.S. Pat. No. 4,562,962 to Hartman discloses a sprinkling system and valve which closes upon displacement of the sprinkler head using an elongated stem connected to a spring biased valve in the main fluid flow line.
U.S. Pat. No. 5,174,500 to Yianilos discloses a sprinkler system with a valve that closes when a sprinkler head is broken or removed, cutting off the flow of water through the head. A bifurcated actuator is connected to a valve head within the riser and is maintained in place when the head is connected. Removal of the head allows the valve to move upwardly by water pressure to close the fluid flow opening between the head and riser.
U.S. Pat. No. 5,335,857 to Hagon shows a flood prevention device for a sprinkler head using a first pipe slidable within a second pipe and a stopper that operates under fluid pressure to seal a removed head.
U.S. Pat. No. 6,499,678 to Hope shows a shut-off mechanism for a sprinkler system having a built-in shut-off valve permitting removal and/or replacement of the head.
U.S. Pat. No. 6,263,912 to Brown et al discloses a fluid flow control valve using a ball valve for stopping the flow of water when abnormal conditions are sensed. The structure includes fingers which deflect for controlling the movement of the ball to a closure position.
U.S. Pat. No. 4,842,198 to Chang, U.S. Pat. No. 5,372,306 to Yianlos and U.S. Pat. No. 6,178,982 to Longstreth disclose other sprinkler systems wherein a valve is closed upon sensing a broken sprinkler head.
As shown above, the prior art has addressed this problem, but a satisfactory and cost effective means of solving this problem is still needed. The present invention provides a sprinkler system overcoming the shortcomings of the prior art.